🚑 first aid: add micro-documentation on the level of READMEs in the folders?

I think it would help having a super brief README generated in each folder, same for each community. Especially starting with `metadata` and `resources` (`lab` can be later), saying:

- [ ] what folder is for what
- [ ] link to the generated page (specific for the community)
- [ ] ideally also which files are what (especially the ones added manually)
- [ ] and even better which columns should be editted by human curation